Project Owner (Legacy) receives PERMISSION_DENIED for Resource Manager and Firestore

Hello Google Cloud Community,

I need assistance troubleshooting an IAM permission issue on a Google Cloud project.

Project details:

• Project name: Djanji Soetji Payment

• Project ID: djanji-soetji-payment

• Organization: No organization

• IAM role: Owner (Legacy)

Problem:

My account is listed as the project Owner in IAM and Manage Resources, but I receive the following errors:

• resourcemanager.projects.get — Permission denied

• datastore.databases.list — Missing permission

• Policy Troubleshooter — Insufficient permissions

Running gcloud projects describe also returns PERMISSION_DENIED.

Troubleshooting already performed:

1. Verified the correct Google account and Project ID.

2. Confirmed the Owner (Legacy) role in IAM.

3. Confirmed the project appears in Manage Resources.

4. Restarted Cloud Shell.

5. Attempted to refresh authentication.

6. Checked Policy Troubleshooter.

The issue persists.

Could someone help identify why API access is denied even though the account has the Owner role?

Thank you.